Police in Pakistan say at least eight people were killed and 20 injured when gunmen opened fire as worshippers gathered for Friday prayers.

The attack on members of the minority Ahmadiyya sect took place near the town of Mandi Bahauddin in Punjab.

The Ahmadiyya profess allegiance to Islam, but were declared heretical by a constitutional amendment 30 years ago.

Police official Mohammed Arif said the gunmen rode up on motorbikes before entering the mosque and opening fire.

'Religious terrorism'

"So far we only know that three men riding on a motorcycle suddenly came into the village [of Mong] on Friday morning. Two of them went inside the mosque and started firing," he told the Associated Press.